Monitoring Stack with Cephadm

The Ceph dashboard makes use of prometheus, grafana, and related tools to store and visualize detailed metrics on cluster utilization and performance. Ceph users have three options:

  1. Have cephadm deploy and configure these services. This is the default when bootstrapping a new cluster unless the --skip-monitoring-stack option is used.

  2. Deploy and configure these services manually. This is recommended for users with existing prometheus services in their environment (and in cases where Ceph is running in Kubernetes with Rook).

  3. Skip the monitoring stack completely. Some Ceph dashboard graphs will not be available.

Deploying monitoring with cephadm

By default, bootstrap will deploy a basic monitoring stack. If you did not do this (by passing --skip-monitoring-stack, or if you converted an existing cluster to cephadm management, you can set up monitoring by following the steps below.

  1. Enable the prometheus module in the ceph-mgr daemon. This exposes the internal Ceph metrics so that prometheus can scrape them.:

    ceph mgr module enable prometheus
  2. Deploy a node-exporter service on every node of the cluster. The node-exporter provides host-level metrics like CPU and memory utilization.:

    ceph orch apply node-exporter '*'
  3. Deploy alertmanager:

    ceph orch apply alertmanager 1
  4. Deploy prometheus. A single prometheus instance is sufficient, but for HA you may want to deploy two.:

    ceph orch apply prometheus 1    # or 2
  5. Deploy grafana:

    ceph orch apply grafana 1

Cephadm handles the prometheus, grafana, and alertmanager configurations automatically.

It may take a minute or two for services to be deployed. Once completed, you should see something like this from ceph orch ls:

$ ceph orch ls
NAME           RUNNING  REFRESHED  IMAGE NAME                                      IMAGE ID        SPEC
alertmanager       1/1  6s ago              0881eb8f169f  present
crash              2/2  6s ago  mix           present
grafana            1/1  0s ago       f77afcf0bcf6   absent
node-exporter      2/2  6s ago             e5a616e4b9cf  present
prometheus         1/1  6s ago                e935122ab143  present

Disabling monitoring

If you have deployed monitoring and would like to remove it, you can do so with:

ceph orch rm grafana
ceph orch rm prometheus --force   # this will delete metrics data collected so far
ceph orch rm node-exporter
ceph orch rm alertmanager
ceph mgr module disable prometheus

Deploying monitoring manually

If you have an existing prometheus monitoring infrastructure, or would like to manage it yourself, you need to configure it to integrate with your Ceph cluster.

  • Enable the prometheus module in the ceph-mgr daemon:

    ceph mgr module enable prometheus

    By default, ceph-mgr presents prometheus metrics on port 9283 on each host running a ceph-mgr daemon. Configure prometheus to scrape these.

  • To enable the dashboard’s prometheus-based alerting, see Enabling Prometheus Alerting.

  • To enable dashboard integration with Grafana, see Enabling the Embedding of Grafana Dashboards.